Sadly, these kinds of mass shootings will likely continue. If anything should have effected change, it should have been the Sandy Hook shooting. TWENTY first-grade children were massacred in that shooting, and it still wasn't enough to change anything.
And no, defeating ISIS isn't going to stop these mass murders, because Sandy Hook wasn't about ISIS. In fact, of the 10 most deadly mass shootings in US history, only 3 of them were related to outside terrorist groups. The other massacres were carried out by angry, disgruntled, and/or mentally ill people. Guess what? Other developed countries around the world have angry and mentally ill people too, but they don't have nearly as many mass shootings per capita as the US does.
It really comes down to more gun control. It's the only solution. But I'm a realist, and I know that won't happen. Not just because of partisan bickering, but more so because gun ownership is etched into the American psyche and American culture, much like car ownership. Guns are an integral part of American culture and family, and the way some fathers spend time with their kids (teaching them how to shoot a gun or go hunting with a gun, for example). Any attempts to restrict that, even just a little, is often perceived as a threat to American culture.
So, I'm resigned with the seemingly inevitable conclusion that mass shootings will continue. There is no reason to believe otherwise.